1. Field of the Invention
The invention relates in general to a program method and a data recovery method, and more particularly to a program method and a data recovery method applied on a multi-level cell (MLC) flash memory.
2. Description of the Related Art
In the present age, non-volatile memory devices have become more popular for use in various electronic devices. For example, flash memory is one of the most popular non-volatile semiconductor memories applied in the present age. In detail, flash memory includes flash memory cells with programmable threshold voltages, so that each of the flash memory cells can be programmed to indicate at least one bit of data. In a case of multi-level cell (MLC) flash memory, each memory cells thereof can be programmed with more than two different levels, so that more than one bit of data, e.g. two bit of data, can be stored therein.
Generally, two program cycles have to be applied to each of the MLC cells, so that the two bit of data stored therein can be programmed with designated values. For MLC cells corresponding to a same block (i.e. a unit array for program operation), bits of data, stored therein, programmed in the same first program cycle are arranged as pages, while bits of data, stored therein, programmed in the same second program cycle are arranged as paired pages corresponding to the respective pages.
Conventionally, MLC flash memory suffers from data loss of the pages of the block if power off event strikes in the program cycle of the paired pages of the block. Thus, how to provide a decent program method and a decent data recovery method capable of preventing the data loss of the pages has become a prominent object for the industries.